General Upgrade Information

compiled by Robert Hancock

What can I gain from a processor upgrade?

This depends on the kinds of applications you run. If you run only basic word processing, web browsing, etc. applications on your system you may not notice a significant improvement unless your processor is very slow. However, with more demanding apps - like games for instance! - a more dramatic improvement may be seen.

In games in particular, the performance increase will depend on your video card. If you have a slow video system which is limiting the game's performance, a new CPU will produce little improvement. It seems that in many newer games, however, especially those using highly detailed geometry, the Pentium II processors can cause performance to be CPU limited even with a relatively outdated card like a Riva TNT. Upgrading to any speed of Pentium III (or a newer Celeron, 533A MHz and faster) can provide a noticeable benefit in these circumstances because the Pentium III processor's SSE instructions can provide a significant efficiency boost in geometry transformation performance, which most of the CPU's graphics-related workload relies on. Using a card like a GeForce with onboard transformation and lighting acceleration could probably also provide a performance boost with the existing processor, though at a certain point it will become CPU limited again as well.

As well, if you notice that when your system is running slowly, it is constantly grinding away at the hard disk, a faster processor likely will not speed that up. The only things that would help this are more RAM (to reduce the amount of swapping to disk and allow Windows to use a bigger disk cache) or a faster hard drive.

General upgrade information:

There are two types of Pentium III processors, often referred to by their Intel code names, Katmai and Coppermine. The main difference between the newer Coppermine and the older Katmai Pentium III processors is that the Coppermine uses a .18 micron manufacturing process while the Katmais are .25 micron. This allows them to reach higher clock speeds and use less power. As well, Coppermines have 256K of level 2 cache on the chip itself, which runs at full processor speed, while the Katmais have 512K of level 2 cache on chips next to the processor on the cartridge, which runs at 1/2 processor speed. The faster speed of the Coppermine's cache generally more than makes up for the smaller size in terms of performance.

A note on how to distinguish between Coppermine and Katmai Pentium III CPUs: Pentium III processors of 500 MHz to 600 MHz that are Coppermine CPUs have an E after the speed (i.e. 550E). The ones with no E are the older Katmai version. All Pentium III processors of 650 MHz and higher are Coppermines, so Intel doesn't use the E for these speeds. (Some vendors seem to use the E suffix even with processors of 650 MHz and higher, even though Intel doesn't. All 650 MHz and higher processors are Coppermines.)

Also, the ones with the B on the end use a 133 MHz FSB (front side bus). Other processor speeds for which Intel only makes a 133 MHz FSB version are not marked with the B, these are the ones with MHz ratings not divisible by 50 (667, 733, etc.)

There are two types of Celeron processors to concern ourselves with here as well: the older PPGA type (speeds of 300A, 333, 366.. up to 533 MHz) and the newer FC-PGA type (speeds of 533A, 566, and up). Note that for 533 MHz processors the ones with no A at the end are PPGA while the ones with the A at the end are FC-PGA (see below for what these mean). All Celerons up to 766 MHz run at a 66 MHz FSB speed, while the 800 MHz and up run at 100 MHz bus. Both the PPGA and FC-PGA versions also have full speed on-die cache like the Coppermine Pentium IIIs, but only 128KB of it, which hurts their performance compared to the Pentium IIIs somewhat.

There are 3 main types of processor packages in use:

• Slot 1: The kind originally installed in all of these machines except the L-series, 4100s and some B-series machines, a cartridge which slides into a slot on the motherboard. Both Pentium II and Pentium III processors are available in this format. There are two main subtypes: SECC and SECC2. The actual processor slot is the same and is compatible between the two, but the processor construction is different, as are the retention clips used to hold the processor in place. With SECC, there is a metal plate between the processor and heatsink, while SECC2 has the heatsink contacting the processor core directly for better heat dissipation. There was a third type, SEPP, used for older Celeron processors. Intel says that retention clips made for these processors will hold SECC2 processors as well.
• PPGA (Plastic Pin Grid Array): This fits a type of processor socket called Socket 370. This type of socket, as PGA suggests, has a grid of holes which the processor's pins fit into. PPGA was used on the older Celerons which used a .25 micron manufacturing process. It has the processor core facing downwards, and a metal slug is used to conduct heat up into the heatsink. This means the heat dissipation is not as good as it could be. These type of Celerons do not have SSE instructions.
• FC-PGA (Flip-Chip Pin Grid Array): To allow heat to dissipate more effectively than with PPGA, these processors have the processor "flipped" so it is facing upwards, the heatsink then directly contacts the processor core. These CPUs use the same socket as the PPGA Celerons do, however some pins were reassigned so Socket 370 motherboards, or slocket adapters for Slot 1 machines, need to be compatible with FC-PGA chips for these to work. Socketed Pentium III CPUs use this format, as do later Celerons (often called Celeron IIs) that use the .18 micron manufacturing process. These Celerons have SSE instructions like the Pentium III processors do.

These pictures show what each type of processor looks like:

You can install socketed (PPGA or FC-PGA) processors on a Slot 1 motherboard using a slot-to-socket (or "slocket") adapter card. These have a socket to put the chip into, the slocket adapter then plugs into the processor slot on the motherboard. Typically slockets have a number of jumpers to configure the type of processor you are installing. The options to select may include choosing between an Intel or Cyrix processor, between a PPGA or FC-PGA processor, selecting the desired FSB speed, and selecting the voltage you want the slocket to ask the motherboard to deliver. For the latter two options, there is usually an automatic setting, which you will likely want to use unless you are overclocking the processor.

Intel sells processors in 2 different ways: a retail boxed package, or an OEM package (the OEM packaged processors are meant primarily for system manufacturers). It is probably easiest to buy the the retail boxed version of the processor, as they include a heatsink and fan, as well as a 3 year warranty on the processor. The OEM versions have no heatsink/fan, and no warranty from Intel - the only warranty is from the distributor; of course they are cheaper. If you get an OEM version, you must supply your own heatsink and fan. If you do use a different heatsink/fan than the Intel one, you should make sure that it is made to work with the type of processor you get: SECC, SECC2, PPGA or FC-PGA processors. If you are overclocking your processor, you may want to use a more effective heatsink than the standard Intel model.

This page lists what each part number of retail boxed Pentium III processor refers to. Note that "Advanced Transfer Cache" refers to a Coppermine processor while "Discrete Cache" refers to a Katmai processor.

The standard Intel heatsink/fan for socketed processors should fit fine on all slockets, but a few other larger models may not fit on some slockets because of capacitors, the socket locking lever, or other devices on the slocket blocking it from attaching properly. If you use a different heatsink/fan from the Intel model, you should ideally check the heatsink/fan before buying to make sure it will fit properly, or at least buy from a dealer that will let you return it.

It's important to make sure the heatsink is attached properly so that the processor does not overheat. Look through the gap between the heatsink and the processor package and make sure that the heatsink is fully contacting the processor chip itself (the black part that sticks up for FC-PGA and SECC2 processors). This page on HardOCP has a picture of what it should look like. It also talks about some of the problems using a really big heatsink on some slocket cards.

Removing the Intel heatsink/fan from a boxed SECC2 processor seems to be a real pain. Intel's recommended procedure is to use a special jig and a drill press to drill out the plastic pins that hold it on - uh-huh.. If you want to use a different heatsink/fan you should probably buy the OEM version of the processor that doesn't have one attached. It is possible to remove the heatsink in some other ways, such as the method detailed on this page. The difficulty here owes to the fact that the pins used to attach the heatsink are not meant to be pulled out once installed. This method seems to allow you to remove the clips without breaking them by pushing them out with a screw, but apparently it still requires a fair amount of force.

Different types of processors use different supply voltages to power them. All Intel processors since the Pentium II, at least, have a Voltage ID output that they use to tell the motherboard what voltages to supply. However, the motherboard has to support the voltage the CPU asks for. When you use a socketed CPU using a slocket adapter, and the slocket has voltage selection jumpers, you can select the automatic setting on the slocket, which just passes the voltage ID signal on to the motherboard unchanged, or set the voltage jumpers to a specific voltage, which overrides the CPU's signal and tells the motherboard to supply the voltage you select. However, it's important to remember that most slockets can only tell the motherboard to supply a voltage, the motherboard must support the requested voltage - if it does not, it will probably deliver no power and the CPU won't work. Some slockets have a regulator onboard that can supply any voltage to the processor regardless of whether the motherboard supports it. See the section "What's this about slockets with an onboard regulator?" below for more info on this.

Why would you want to change the voltage from the standard setting it's supposed to use? If you are overclocking the processor, you may have to increase the voltage to make it run properly at the higher speed. See the R-series page for more info on this. Otherwise, since the voltage a processor should use can change between processor types and even different revisions of the same type, you should use the automatic voltage setting if you aren't overclocking to avoid mixups. That way you don't have to worry about any of the stuff in the rest of this section :-)

The table below summarizes what voltage each type of processor uses. If you are overclocking, you should set an initial testing voltage with the standard voltage given in mind.

Some processors have different voltage requirements for different revisions. The model and stepping numbers listed below can be viewed for your processor by running a utility such as WCPUID (see "How can I tell what speed my processor is running at?" below). This is only a guide - newer steppings may use different core voltages. If you really want to be sure, look up your system's CPU on Intel's Pentium III web site in the data sheets. As well, the voltage is usually marked on the newer CPUs.

Additional notes:

The electronics we're dealing with here is sensitive to electrostatic discharge. A static charge built up on your body that's much too small for you to feel any "zap" when you touch things is capable of damaging or destroying a processor or other system components. To avoid this, it's probably best to leave your computer connected to the outlet. To prevent accidentally turning it on while you're working, you may want to connect the machine to a plugged-in power strip, but leave the power strip's switch turned off. That way it can't power up, but the ground wire is still connected to the outlet. While working inside your machine, periodically touch part of the metal chassis to bleed off any static you may have accumulated. Also, avoid unnecessarily touching processor pins or slot contacts.

If you have a grounding wrist strap, you can use that to make sure your body doesn't accumulate any static while you work. You can get an inexpensive one at Radio Shack, part number 276-2397, cost $3.99 ($5.99 in Canada). They also have some fancier ones with a longer cord, etc. but I doubt you need one better than this unless you work inside computers for a living. Basically, you should keep the computer plugged into a powered-off, but still plugged in power strip as I said above, then clip the strap's alligator clip to part of the computer's metal chassis to ground it.

Finally, if you have a Sound Blaster Live! sound card, you should upgrade the drivers for it to the latest available version before upgrading the processor, or you may experience system lockups and/or blue-screen errors after upgrading the CPU. Apparently old versions of 3dfx Voodoo3 video card drivers can cause problems with newer processors as well, if you have one of those cards you should get the latest drivers from 3dfx.

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